The present invention relates to a barrier transition for removably closing road gaps and other passage areas through safety barriers.
As is known, superhighways, freeways and two-carriageway roads in general are protected at their central riserve by safety barriers which can be made of a concrete mix, usually a reinforced concrete mix or, more frequently, a metal material, depending on light and heavy vehicle containment characteristics, and on personal safety standards, defined by national and European rules.
The above protective systems are interrupted, at preset distances, by paved areas to allow transiting vehicles to switch off the carriageway, when conditions are required.
The above mentioned areas are usually called xe2x80x9ctraffic divider gapsxe2x80x9d, and have an average span from 20 to 40 m.
The frequency with which the mentioned road gaps occur through the safety barrier, depends on environment conditions, maintenance requirements, provided outlets or the like and, usually corresponds to a rather small spacing, i.e. about a gap each two road kilometers.
Thus, said road gaps actually represent a discontinuity through the side protective system designed for preventing transiting vehicles from stepping over the traffic divider, i.e. the safety barrier.
Such a discontinuity is very dangerous, since traffic accidents, caused by vehicles traversing the road gap, even if they occur with a rather small rate, have very deleterious effects and, because of the continuously increasing vehicle traffic, are anyhow very significative since, in such a case, an uncontrolled vehicle accidentally traversing a read gap, will probably impact against one or more other vehicles driven in the opposite direction on the other carriageway, thereby the sum of the kinetic energies of the impacting vehicles will be such as to cause fatal consequences for the vehicle passengers.
Moreover, if the starting portions of the safety barrier at the ends of the road gaps are not suitably protected, for example by impact attenuators, then an impact against these regions would frequently have very serious consequences for the vehicle passengers.
Thus, in order to overcome the above problems the possibility of eliminating the mentioned road gaps and closing them by fixed constructions of a conventional barrier type has been already considered.
Such an approach, however, could not be a viable one, for example because of emergency and snow removal vehicle circulating problems, to allow vehicles to switch off their carriageway in serious accident conditions in which the carriageway would be interrupted for a long time, and for long duration maintenance operations, requiring the provision of a counter-lane on the opposite carriageway.
Thus, for safety purposes, it is absolutely necessary to provide the road users with an efficient closure system which, on the other hand, can be easily and quickly removed, for example in urgency situations.
Disassemblable metal conventional barriers are commercially available, which, however, do not allow to provide an easy and quick opening of the barrier since, for disassembling them, it would be necessary to remove a comparatively high number of barrier coupling elements. In this connection it should be moreover pointed out that the mentioned coupling elements, being subjected to atmospheric and polluting agents, would render much more difficult a snap operating intervention.
Fixed cable barriers have been also used in some countries with rather good safety results; however this prior technology disclosed, for example, in EP 369659 (British Ropes) does not allow to make easily removable barrier systems, thereby does not solve the existing barrier problems.
A cable safety system which has been specifically designed to overcome the above problems is that disclosed in the Italian Patent No. 1,270,041 and in WO 00/23658 (PCT) to Snoline. This system, however, does not solve the problems affecting large width road gaps since in an impact situation, it provides comparatively great dynamic deforming cambers.
Accordingly, the aim of the present invention is to solve the above mentioned problems, by providing a barrier transition for removably closing road gaps, adapted to resist, in a completely safe condition, against impacts, as required by international rules for light and average weight vehicles, such as motor vehicles and busses, and which, in the meanwhile, can be either completely or partially removed, in a short time without requiring either specifically designed complex tools or skilled operators.
Within the scope of the above mentioned aim, a main object of the present invention is to provide such a barrier transition which, owing to its specifically designed constructional features, is very reliable and safe in operation.
Yet another object of the present invention is to provide such a barrier transition which can be easily made starting from easily available elements and materials and which, moreover, is very competitive from a mere economic standpoint.
According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by a barrier transition for removably closing road gaps, characterized in that said barrier transition comprises suitably contoured protective longitudinal elements arranged symmetrically to a road gap closure line, said protective elements being coupled to one another so as to provide a longitudinally rigid barrier having impact force transmitting end portions.
Said protective elements have advantageously a length equal to that of standard safety metal barriers, i.e. usually of 4 m, and a conventional double or triple corrugation cross-section, and an optional vertically extending multiple pattern.
The protective elements are coupled in opposite pairs, by rigid connection means, such as screws engaged in holes provided near their end portions, and the element pairs are coupled by special blocks which, on a side, are rigidly clamped by screws to the holes of said elements and, on the other side, support either one or two vertical hinge assemblies.
Said hinge assemblies, of strong construction, connect the system to allow it to transmit through said protective elements the stresses from an impacting vehicle, thereby providing a comparatively high flexural stiffness, to in turn reduce the maximum dynamic camber.
Thus, the system substantially operates as a flexible barrier, which is exclusively stressed by tension and strained through a resilient range.
The pin of the hinge assembly can be easily removed to quickly either partially or fully open the transition barrier (i.e. to remove one or more elements thereof), for allowing traffic to pass therethrough.
Each longitudinal protective element is coupled to two vertically extending feet, arranged near its end portions and supporting it on the ground thereon it can freely slide.
To facilitate the opening movement, some or all said feet can comprise a plurality of wheels the height of which can be adjusted by a suitable raising or lifting mechanism coupled to said feet or to said longitudinal protective elements, to allow said wheels to contact the ground, in an extended position thereof, only as the road gap is opened. The wheels can moreover comprise a brake for preventing spontaneous movements on an inclined ground.
To the end elements of the transition, which transition can have any desired length, depending on the existing road gap size, transition fitting of any suitable shape designed to provide a safe connection to the fixed barrier are coupled, said fittings comprising the same panels as said fixed metal barrier having a double or triple corrugation construction, or different modified panels for concrete barriers, in each case provided in a suitable number and arrangement of the holes for coupling and transmitting the impact force to be dissipated by the extended fixed barrier, which, usually, has a length of the order of at least few hundred meters, but which, most probably, continuously extends up to the following road gap with a length of at least two kilometers.
If the existing barrier pertains to a less class and, accordingly, is too weak to absorb the impact force, then it would be anyhow possible to discharge to the ground said impact force, by coupling the transition end elements to a strong pole ground driven or coupled to a suitable foundation adding optional dissipating elements, for providing protection against a local side impact.
If only a portion of the road gap shall be opened, then it is advantageously possible to use a suitable removable pole, to be driven into the ground through a driving pole bush, for anchoring therein the transition portion remaining as the barrier gap is opened.
To further decrease the dynamic camber, the system can also comprise intermediate binding elements, including further removable ground driven poles for reducing the overall system working length and, accordingly, its dynamic deformation.